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Thining fiberglass resin to spray. Is it possible?

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57K views 17 replies 12 participants last post by  MARTINSR  
#1 ·
I was not sure where to post this. It is interior related, But I believe you guys can better answer.



A long time ago I was watching an episode of "American hotrod" (The boyd coddington show RIP) I don't remember what episode. But in the episode they thinned some mixed fiberglass resin and sprayed a thin coat over a smooth gel-coated fiberglass dash panel and then wrapped the dash with a leather looking vinyl backwards, so the leather grain print was face down in the fiberglass resin. After the resin cured they pulled the vinyl/leather off and it left a perfect factory leather looking imprint on the dash. They sprayed it with a Tan/Khaki colored single stage urethane with a flattening additive for a hard satin finish. It looked perfect. Just like the hard plastic interior trim.

It was real interesting and creative.. Something Ive wanted to try for a wile now. After a few attempts Im out of ideas on how to thin down fiberglass resin and keep its harding property's. Does anyone know of a fiberglass resin thinner?

here is what I have already used that has failed.

Lacquer thinner:
Thinned the resin, Sprayed milky white & never hardened.
MEK (methyl ethyl ketone):
same as the lacquer thinner.
Mineral spirits: Would not mix. The mineral spirits floated on top like oil and water.
Urethane reducer (nason med):
Turned the resin in to jello and took 24hrs to harden. could not be sprayed.


Anyone know anything about this process? Or how to thin fiberglass resin so it can be sprayed from a cheap Harbor freight 1.5 gravity spray gun.

And do you think I could do this process and use urethane 2K clear rather then fiberglass?

Thanks for your time!
 
#2 ·
reply

try using t-10 epoxy reducer, and after that try xylene. but dont try to thin it so much that you can use a conventional pot gun. try keeping it a little thicker(reduce as little as possible), and using a large tip(5-17 through 6-21) on an airless paint sprayer. this will allow the neccessary mil build without the overthinning that has ruined the earlier work you have done. t-10 is epoxy thinner, for all epoxy base, and xylene, while only for xylen based paint, serves as a suitable accelerant/reducer for urethanes, and several types of enamels and spar too. just gotta test what you do first. a litttle xylene goes a very long way, as you will see. dont forget to flush the sprayer with laq thinner after, then get the laq out with very warm, not scalding, soap water. then cold clean water. laq in the lines eats the packings and delrin seals in quality paint sprayers. I have been painting for 15 years. this is my best advice, BUT i dont know for sure what chemical will properly thin the material you are using, due to several variables that are out of my control. good luck, and wear a good mask, that stuff WILL kill you.
 
#4 · (Edited)
reason # 557 why I hate those televison shows...all of em...

I'm not really sure what kind of resin they used, the most common type is polyester.


If you want to thin polyester resin use styrene. Styrene is the solvent that makes that resin a liquid. You can buy it straight from the fiberglass supply shop. No more than 5% would be my guess, try it and see.
In the 25 years I've been doing fiberglass work, I've never had to thin resin except for one type of application. (you thin resin with styrene or acetone about 2-5 % then brush it on wood, like a primer when you want to make a tie coat to glass over the wood, then let it kick before you layup with the real resin...we always felt that it was a cheap and dirty hack way of getting polyester resin glass to stick to wood a little better..) I would not use acetone to thin resin that was going to be under any kind of paint.

I would not do it like that myself, I'd use a brush and or a roller, and unthinned resin. Unthinned resin sprays well using a pressure pot and a gun with the biggest tip you can find...2.5 mm is good, 3.0 is probably better. Wash the gun with acetone. 3 rinses and it'll live to see another day.

Any type of solvent you add to resin will weaken it.

I hope those tv guys sanded the gelcoat first, resin does not stick to unsanded gelcoat very well.

The other thing that is strange to me is that leather has a texture that is composed of small, randomly shaped raised sections seperated by tiny little valleys, when you make an imprint of that you get the exact opposite, small randomly shaped low spots seperated by tiny little mountains....But I guess it worked alright for those guys...

later, mikey
 
#5 · (Edited by Moderator)
here are my unfrofessional thoughts. I,ve done work on a fiberglass kit car, the only thing that we used to thin out resin would be acetone, a.k.a. nailpolish remover. we just used it for cleaning up tools and equiptment. why can't you just use a roller and put it on that way? if the material you use for the leather pattern is all cut out, my worry is that the resin will kick before your done fitting everything, and what if some spots didn't catch the pattern? too many things can go wrong, in my opinion, wouldn't it be easier to just get a piece of leather or nice quality vinyl and glue it on?
 
#6 ·
leather grain

The factory method of matching leather grain on vinyl was to use mold release on the original materal then make the mold material off of that, for small holes and tears a scrap of the final material was heated with a heat gun, scraped off with a putty knife and applied to the backside first then blended onto the front. A backup piece of metal was used and the the front was heated then the pattern was held on the top until it cooled. sometimes touch-up spray had to be used. If you have ever had a lump in a seat cover that could be why.
 
#8 ·
the fastest and easiest way to thin either type of resin is to heat it up, approx 110F with do fine, they will both get thinner than water. CLEAN out the gun NOW, it will set-up quickly. the nice part is the resin is NOT thinned when it is cooled off and on the part, no chem problems later.

It would be easier just to use gelcoat, tint it to any color you wish.
 
#11 ·
Thanks for all the info. After a few small projects Im now looking for a copy of that episode to see what I missed, Or if they pulled one over on me.

I used a 12" square of a vinyl/leather and some photo paper. I used an ink roller that came with a kit my wife bought to make foot prints of our son.
I rolled the vinyl and pressed it to the photo paper and found out two things.
#1: You can NOT get a usable print from leather/vinyl using fiberglass. The grain is not deep enough. #2 As stated above when using the vinyl to make an imprint it does not mirror the the leather grain. The groves in the leather would become the high points. It would be a negative impression. thus looking like ****.


If anyone has any info on the episode of American hot rod where they are building a 40's or 50's olds that was painted a dark metallic purple with tan and white interior let me know. I can not find the episode.
 
#13 ·
Paintguy said:
Why go to all that trouble? They might as well have just covered it in vinyl surely? :confused:

Im wanting to do a radio bezel, and don't have the clearance to warp in vinyl.

Ive gave up. Not many people cared enough to record American hotrod and post it online. I can't find the episode, And the more I think about it the more unrealistic it seems.
 
#14 ·
I'm thinking you get some vinyl sticker with a leather like texture on it, I have seen it. Then apply it like you would a large decal with water and heat. You can do some amazing things with a heat gun and vinyl "appliques".

Brian
 
#16 ·
I doubt HRBB did some trickery on the show . I believe they had a product designed for the application.. I cannot attest to the quality of their result but I do not doubt they had a sheet of grain pattern in the process you describe.

For your small project you can make your own transfer sheet. The processs is simple enough, only taking a bit of your time..

The proccess of moulding your part will require more trial and error to get the desired result.

http://www.leatherworldtech.com/LeatherGraining.aspx
 
#17 ·
I was thinking about this thread yesterday, mostly trying to figure out how to prep such a intricate design in fiberglass for paint without defacing the surface, or have paint flaking off the panel.

Then I was wondering what would happen if you pushed this design onto a marbleizer base coat if it would turn out with the desired effect...